Difference Between Flash Point and Boiling Point

Thekey differencebetween flash point and boiling point is that theterm flash point is applied for a易挥发的liquid, whereas the term boiling point can be applied for any liquid.

Flashpoint and boiling point are two terms we use regarding the liquid state of substances. Flashpoint specifically applies for volatile liquids because it is the lowest temperature at which汽of the volatile liquid can undergo ignition. On the other hand, the boiling point is the temperature at which the vapour pressure of a liquid equals the external pressure surrounding the liquid. Every liquid has a boiling point, but only volatile liquids have a flash point.

内容

1.Overview and Key Difference
2.What is Flash Point
3.What is Boiling Point
4.Side by Side Comparison – Flash Point vs Boiling Point in Tabular Form
5.概括

What is Flash Point?

Flash point is the lowest temperature at which vapour of the material will ignite when given an ignition source. We often confuse with fire point and flash point, thinking both are the same. But, fire point gives the lowest temperature at which the vapour of a substance can keep burning when we remove the ignition source, which is completely different from the definition of flash point.

在考虑蒸气的点火时，在闪点处，当我们提供点火源时，有足够的蒸气来诱发点火。挥发性液体具有独特的浓度flammable汽, which is necessary for sustaining the combustion in air.

If we are to measure the flash point of a substance, there are two methods: open cup measurement and closed cup measurement. Furthermore, the methods of determining the flash point are specified in many standards.

What is Boiling Point?

Boiling point is the temperature at which the vapour pressure of a liquid becomes equal to the external pressure surrounding the liquid. Hence, the boiling point depends on theatmospheric pressure. Here, we can observe a higher boiling point at higher external pressure. Usually, water boils at 100⁰C. Since the atmospheric pressure is lower at higher altitudes, water will boil between 80⁰C – 90⁰C.这将导致未煮熟的饭菜。

当液体的温度在相应的饱和压力下超过其饱和温度时，液体的沸腾发生。饱和温度是对应于液体可以保持的最高热能的温度，而无需在给定压力下将其状态更改为蒸气。饱和温度也等同于液体的沸点。当液体的热能足以打破分子间键时，就会沸腾。正常的沸点是在大气压下的饱和温度。沸点仅在triple point和critical pointof the liquid.

What is the Difference Between Flash Point and Boiling Point?

Flash point is the lowest temperature at which vapour of the material will ignite when given an ignition source. Boiling point is the temperature at which the vapour pressure of a liquid equals the external pressure surrounding the liquid. So, the key difference between flash point and boiling point is that every liquid has a boiling point, but only volatile liquids have a flash point.

此外，在液体的闪点，我们可以在沸点上方观察液体上方的点火，我们可以观察到液体内的气泡的形成。因此，这是闪点和沸点之间的显着差异。如果我们看一下它们的机制，则在闪点处的点火源存在的情况下，会发生点火蒸汽的点火，当有足够的蒸气诱发点火开关时。但是，在沸点，液体的蒸气压变得等于液体周围的外部压力。

概括– Flash Point vs Boiling Point

Flash point and boiling point have several important differences between them. The key difference between flash point and boiling point is that the term flash point is applied for a volatile liquid, whereas the term boiling point can be applied for any liquid.

Reference:

1. Helmenstine, Anne Marie. “Definition of Boiling Point in Chemistry.” ThoughtCo, May. 7, 2019,Available here.
2. “Boiling Point.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 20 Feb. 2018,Available here.

Image Courtesy:

1. “Flaming cocktails” By Nik Frey (niksan) –(CC BY 2.5)viaCommons Wikimedia
2. “194034” (CC0) viaPexels